John Usher

the wand — handwritten in the air, glowing blue on black

the wand — write in the air, type into anything

2025 → now · co-founder · edge ml · nRF54LM20B

Co-founded Input-A (Inputa Inc., Delaware) to build the wand, which types what you write in the air: first a handheld, the wandBox, then a signet ring for smart glasses, the wandRing. A compact neural net reads handwriting from a few-dollar motion sensor — recognition runs on the device in 25–28 ms on Nordic's nRF54LM20B, no camera, no cloud — and it connects to TVs, phones, computers and glasses as a standard Bluetooth keyboard. Twenty years of small-silicon audio ML, pointed at motion instead of sound. Measured on 490+ paid study participants across 28 studies, scored on writers the model has never seen. Six provisional patent families filed. TVs today; the glasses era is the point — a 3D-printed test ring already reads my handwriting (the write-up).

→ the-wand.ai → about → try it in your browser

The detector's own output: an infrared night-camera frame at 03:53, a red box drawn round the raccoon and a RACCOON DETECTED banner

racoon_alert — who’s raiding the pond

2026 · python · onvif · megadetector · speciesnet

I live in Berlin, and raccoons were raiding my pond — bothering the sticklebacks and the bitterling. I wanted to see how they were breaking in.

No vendor cloud anywhere in it. Reverse-engineering the camera settled that: its pan/tilt runs through the manufacturer’s servers in plaintext, so everything useful comes over RTSP and ONVIF instead — the open standard these cameras speak without their app. Nights are the hard part: MegaDetector finds the animal in the infrared frame and SpeciesNet names the species, which is why a black cat in the bushes is no longer e-mailed home as person 0.74. Next is the whole thing standing alone on a Raspberry Pi with no route out — though detecting, unlike viewing, needs an NPU to keep up.

→ source → the 03:53 clip

ARP8 — acoustic arpeggiator

2026 · web midi · javascript

A browser MIDI arpeggiator for Korg Berlin's phase8 — the eight-voice acoustic synthesizer with steel resonators. Twenty-eight hand-authored generative compositions (Bach, Reich, Eno, Pärt, Cage, Satie…), each a different musical territory using one engine. Runs in Chrome over Web MIDI — no installer, no DAW.

→ live → source

Nautic Audio — carbon-fibre active loudspeaker

w/ Amon Tobin

Co-founded loudspeaker company. Engineered an all-carbon-fibre active tower with a novel waveguide aimed at the listening seat to suppress room coloration. Voiced in collaboration with composer / producer Amon Tobin.

→ video → amon's notes

light-chat

go · whisper · gpt · arduino

Speak a wish at a Raspberry Pi → Whisper transcribes → GPT writes a fresh Arduino sketch → the lights reprogram themselves. Conversational firmware, end-to-end.

→ source

ardpifi

go · pi · arduino · ad-hoc wifi

Programmable LED controller running across an ad-hoc Wi-Fi mesh of Pi + Arduino nodes. No router, no cloud — just peers.

→ source

Spatial pickup & beamforming

video · archive

An older demo of microphone-array beamforming — picking out a single voice in a noisy room without losing the room.

→ video

Node — sci-fi novella

prose · 2024

Long-form fiction. Audio engineers do other things too.

→ pdf → repo

Twenty years engineering at the edge. Dolby Atmos. Smart earphones. Now air-writing.